21000012221200 has 60 divisors (see below), whose sum is σ = 50465124311040. Its totient is φ = 8397907914880.

The previous prime is 21000012221183. The next prime is 21000012221203. The reversal of 21000012221200 is 212221000012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21000012221203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4948240 + ... + 8153839.

It is an arithmetic number, because the mean of its divisors is an integer number (841085405184).

Almost surely, 2^{21000012221200} is an apocalyptic number.

21000012221200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000012221200 is an abundant number, since it is smaller than the sum of its proper divisors (29465112089840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21000012221200 is a wasteful number, since it uses less digits than its factorization.

21000012221200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13106104 (or 13106093 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21000012221200 its reverse (212221000012), we get a palindrome (21212233221212).

The spelling of 21000012221200 in words is "twenty-one trillion, twelve million, two hundred twenty-one thousand, two hundred".